A liquid crystal display device includes a liquid crystal display panel and a polarizing plate and at least one of the liquid crystal display panel and the polarizing plate has a deformed planar shape that is not a quadrangular shape. The polarizing plate has a first alignment mark and an alignment film has a second alignment mark as bonding marks. The alignment film and the polarizing plate are positioned each other according to the first and the second alignment marks and bonded to each other. Such a liquid crystal display panel included in the liquid crystal display device is described in WO 2007/108244.
Components such as the backlight device that supplies light to the liquid crystal display panel having a deformed shape other than the quadrangular shape also has a deformed shape other than the quadrangular shape similar to the liquid crystal display panel. Therefore, if the backlight device that is mounted on the liquid crystal panel is shifted from a correct position, use efficiency of light supplied by the backlight device may be lowered.